Distribution of Frasnian and Famennian Ostracods in the Northwestern Kuznetsk Basin (Western Siberia)

Ostracod assemblages from Upper Devonian sections of the northwestern vicinity of the Kuznetsk Basin on the Tom River are studied. In the studied region, biostratons were recognized at the rank of beds with fauna (Beds with Bairdia vassinoensis, Beds with Hollinella valentinae, Beds with Acratia granuliformis). Based on the quantitative analysis of ostracod assemblages at the generic level, dominant taxa were identified. Seven characteristic associations were recognized (Bairdia–Moorites, Moorites–Amphissites, Amphissites–Bairdia, Bairdia–Bairdiocypris, Amphissites–Hollinella, Acratia–Bairdiocypris, Knoxiella–Moorites), which were confined to the shallow parts of the paleobasin from the Middle Frasnian to the Early Famennian.